5/16-18 x 3 Coarse Hex Cap - Grade 5 Box/100

Overview

The Midwest Fastener 5/16-18 x 3 Coarse Hex Cap Screw (MPN: 281) is designed for general construction, mechanical assembly, and structural fastening applications requiring a high-strength, standardized threaded fastener.

Technical Features

• Grade 5 High-Strength Construction: Meets SAE Grade 5 strength requirements, providing greater tensile and proof load capacity compared to Grade 2 fasteners — suitable for medium- to high-stress structural connections.
• Zinc Finish: Electroplated zinc coating provides a baseline level of corrosion resistance, extending service life in indoor and moderately exposed environments.
• 5/16-18 Coarse Thread: Coarse thread pitch allows faster engagement and assembly, and provides better resistance to cross-threading in softer base materials.
• Hex Drive Head: Standard hex cap head is compatible with common wrenches and sockets, enabling high-torque installation with widely available tooling.
• 3-Inch Length: Provides sufficient thread engagement depth for fastening through thicker material stacks or into structural members.
• Box of 100: Bulk packaging at 3.91 lb per box supports project-quantity purchasing and reduces per-unit cost for high-volume fastening tasks.

Applications

• General construction framing and structural assembly where Grade 5 tensile strength is specified.
• Mechanical equipment assembly requiring standardized coarse-thread hex fasteners.
• Automotive, agricultural, and industrial maintenance repairs calling for SAE Grade 5 hardware.
• Wood-to-metal or metal-to-metal connections where a 3-inch length provides adequate clamping depth.
• Job-site and shop inventory stocking where bulk quantities of a common fastener size are required.